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ment and Desormes regards carbonic acid, which, body, in cooling a certain thermometric range at being reduced to the standard of weights, gives a high temperature, gives out the same quantity a specific heat compared to air of about 0:987 to of heat that it does in cooling through the same 1.000, while oxygen is only 0.9000. The former range at a lower temperature? No means seem tables of Crawford and Dalton give the specific better adapted for solving this problem, than to heat of oxygen 2:65, and of carbonic acid 0.586, measure the refrigeration produced, by the same compared to air 1.000. · And, upon these very weights of ice, on uniform weights of water, at erroneous numbers, they reared their hypothe different temperatures. Mr. Dalton found in tical fabric of latent heat, combustion, and the this way, that * 176.5° expresses the number of animal temperature.
degrees of temperature, such as are found We see from the experiments on air, at dif- between 200° and 212° of the old or common ferent densities, that its specific heat diminishes scale, entering into ice of 32° to convert it into in a much slower rate than its specific gravity. water of 32°; 150° of the same scale, between When air is expanded to a quadruple volume, 122° and 130°, suffice for the same effect; and its specific heat becomes 0.540, and, when ex- between 45o and 50°, 128° are adequate to the panded to eight times the volume, its specific conversion of the same ice into water. These heat is 0.368. The densities in the geometrical three resulting numbers (128, 150, 176-5), are progression 1, 1, 1, , correspond nearly to the nearly as 5, 6, 7. Hence it follows, that as specific heats in the arithmetical series 5, 4, much heat is necessary to raise water 5° in the 3, 2. Hence also the specific heat of atmo- lower part of the old scale, as is required to spherical air, and of probably all gases, consi- raise it 7° in the higher, and 6° in the middle.' dered in the ratio of its weight or mass, dimi- See his New System of Chemical Philosophy, nishes as the density increases. On the principle vol. i. p. 53. of the increase of specific heat, relative to its “Mr. Dalton, however,' says Dr. Ure, ‘instead mass, has been explained the long observed phe- of adopting the obvious conclusion, that the capanomenon of the intense cold which prevails on city of water for heat is greater at lower than it the tops of mountains, and generally in the is at higher temperatures, and that therefore a upper regions of the atmosphere; and also that smaller number of degrees at the former should of the prodigious evolution of heat, when air is melt as much ice as a great number at the latter, forcibly condensed. According to M. Gay Lus- ascribes the deviation denoted by these numbers, sac, a condensation of volume, amounting to 5, 6, and 7, to the gross errors of the ordifour-fifths, is sufficient to ignite tinder. If a nary thermometric graduation, which he consisyringe of glass be used, a vivid flash of light is ders so excessive, as not only to equal, but seen to accompany the condensation.
greatly to overbalance the really increased spe
cific heat or capacity of water; which, viewed in Table IV.–Of Specific Heats of some Solids itself, he conceives would have exhibited oppodetermined by Dulong and Petit. site experimental results. That our old, and,
according to his notions, obsolete thermometric Specific Weight of Product
scale, has no such prodigious deviation from heats, that the atoms, of these
truth, is, I believe, now fully admitted by cheof water oxygen be- two num
mical philosophers; and therefore the only legibeing 100.
bers. timate inference from these very experiments of
Mr. Dalton is the decreasing capacity of water, Bismuth
0.0288 13:300 0.3830 with the increase of its temperature. It deserves Lead
0·0293 12.950 0.3794 to be remarked, that my experiments on the Gold
0.0298 12:430 0.3704 relative times of cooling a globe of glass, succesPlatinum 0.0314 11.160 0.3740 sively filled with water, oil of vitriol, common Tin
0.0514 7.350 0:3779 oil, and oil of turpentine, give exactly the same Silver,
0.0557 6.750 0.3759 results as Mr. Dalton had derived from mixtures Zinc
0:0927 4.030 0.3736 of two ounces of ice with sixty of water, at difTellurium 0·0912 4.030 0:3675 ferent temperatures. This concurrence is the more Copper 0.0949 3.957 0.3755 satisfactory, since, when my paper on the speNickel
0:1035 3.690 0:3819 cific heats of the above bodies, published in the Iron
0 1100 3.392 0.3731 Annals of Philosophy for October 1817, was Cobalt
0:1498 2.460 0.3685 written, I had no recollection of Mr. Dalton's Sulphur 0.1880 2.011 0.3780 experiments.'
Table V.-Of Capacities for Heat. The above products, which express the capa
Mean capacity cities of the different atoms, approach so near
Mean capacity between
between 0° and
00 and 1000 equality, that the slight differences must be owing
3000°. to slight errors, either in the measurement of the capacities, or in the chemical analyses, especially Mercury 0.0330
0.0350 if we consider, that, in certain cases, these errors, Zinc
0.1015 derived from these two sources, may be on the Antimony
0·0549 same side, and consequently be found multiplied Silver
0.0611 in the result. Each atom of these simple bodies Copper . 0·0949
0.1013 seems, therefore, as was formerly stated, to have Platinum 0.0355
0.0355 the same capacity for heat.
0.1900 The question may here be asked, Whether a
The capacity of iron was determined at the elevation of their temperature, that it becomes four following intervals :
an easy task to ascertain within certain limits From 0 to 100°, the capacity is 0·1098
the augmentation of volume which liquids and 0 to 200
gases suffer through a moderate thermometric 0 to 300
range. We have only to enclose them in a glass
0.1255 0 to 350
vessel of a proper form, and expose it to heat.
But to determine their expansion with final ac*If we estimate, continues Dr. Ure, the curacy, and free the results from the errors temperatures, as some philosophers have pro- arising from the unequable expansion of the reposed, by the ratios of the quantities of beat cipient, is a problem of no small difficulty. It which the same body gives out in cooling to a seems, however, after many vain attempts by determinate temperature, in order that this cal- preceding experimenters, to have been finally culation be exaci, it would be necessary that the solved by MM. Dulong and Petit. The expanbody in cooling, for example, from 300° to 0°, sion of 'solids had been previously measured should give out three times as much heat as in with considerable accuracy by several philosocooling from 100° to 0°, But it will give out phers, particularly by Smeaton, Roy, Ramsden, more than three times as much, because the and Troughton, in this country, and Lavoisier capacities are increasing. We should therefore and Laplace in France. The method devised find too high a temperature. We exhibit in the by general Roy, and executed by him in confollowing table the temperatures that would be junction with Ramsden, deserves the preference. deduced by employing the different metals con- The metallic or other rod, the subject of experitained in the preceding table, We must suppose ment, was placed horizontally in a rectangular that they have been all placed in the same liquid trough of water, which could be conveniently bath at 300°, measured by an air thermometer. heated. At any aliquot distance on the rod, Iron
332-20 two micrometer microscopes were attached at Mercury
318.2 right angles, so that each being adjusted at first Zinc
328.5 to two immoveable points, exterior to the heating Antimony
apparatus, when the rod was elongated by heat, Silver
the displacement of the microscopes could 'be Copper
320-0 determined to a very minute quantity, to the · Platinum
317.9 twenty or thirty thousandth of an inch, by the Glass
micrometrical mechanism. PART II.
Dr. Ure, in the years 1812 and 1813, made,
he tells us, many experiments with a micromeOF THE GENERAL SYMPATHIES OF HEAT trical apparatus of a peculiar construction, for WITH THE DIFFERENT FORMS OF MATTER. measuring the dilatation of solids. I was par
The effects of heat are either transient and ticularly perplexed,' he says, 'with the rods or physical, or permanent and chemical, inducing zinc, which, after innumerable trials, I finally a durable change in the constitution of bodies. found to elongate permanently by being alterThe latter effect we have already treated of in nately heated and cooled. It would seem that our article COMBUSTION. The first is to be dis- the plates composing this metal, in sliding over cussed here; and divides itself into the two each other by the expansive force of heat, present heads, of changes in the volume of bodies while such an adhesive frietion as to prevent their enthey retain their form, and changes in the state tire retraction. It would be desirable to know of bodies.
the limit of this effect, and to see what other 1. The successive increments of volume which metals are subject to the same change. - I hope bodies receive with successive increments of to be able, ere long, to finish these pyrometrical temperature, have been the subjects of innumer- researches.' The doctor then gives us the folable researches. The expansion of fluids is so lowing copious tables of dilatations, compiled much greater than that of solids, by the same from the best experiments :
Table I.—Linear Dilatation of Solids by Heat.
in Vulgar Glass tube,
1.00083333 Fractions, Do.
Dulong and Petit,
Lavoisier and Laplace, 1.00081166
Roy, as glass, Platina,
Dulong and Petit,
1.00099180 Do. and glass,
TABI E I.—Linear Dilatation of Solids by Ileat.- Continued
in Vulgar Antimony,
Fractions. Cast iron prism,
Lavoisier, by Dr. Young, 1.00111111
1.00118990 Steel rod,
Phil. Trans. 1795, 428, 1.001 12500
Lavoisier and Laplace, 1.00107875
926 Do. tempered yellow,
1.001 18980 Hard steel,
1.00122500 Annealed steel,
1.00122000 Tempered steel.
1.00125800 Soft iron forged,
Lavoisier and Laplace,
Dulong and Petit,
1:00139200 Annealed gold,
Ellicot, by comparison, 1.00150000
Lavoisier and Laplace,
1.00146606 Do. Paris standard, unannealed, Do.
Lavoisier and Laplace,
Dulong and Petit,
1.00171821 ਝਉਣ Brass,
Lavoisier and Laplace, 1.00186671
1.00185540 Cast brass,
1.00187500 English plate-brass, in rod,
1.00189280 Do. do. in a trough form, Do.
1.00191880 Brass wire,
1.00216000 Copper 8, tin 1,
Ellicot, by comparison, 1.0021000
Lavoisier and Laplace, 1.00190974
1.0020826 Brass 16, tin 1,
1.00190800 Speculum metal,
1.00193300 Spelter solder; brass 2, zinc 1, Do.
1.00205800 Malacca tin,
Lavoisier and Laplace, 1.00193765 512
1.00228300 Grain tin,
1.00284000 Soft solder; lead 2, tin 1,
1.00250800 Zinc 8, tin 1, a little hammered, Do
Lavoisier and Laplace, 1.00284836
1.00294200 Zinc, hammered out į inch per foot, Do.
1.00301 100 Glass, from 32° to 212°,
Dulong and Petit
957 The last two measurements by an air thermometer.
Table II.–Dilatation of the volume of Liquids by being heated from 32° to 212o.
Do. Lord Charles Cavendish
Lavoisier and Laplace
Dulong and Petit
do. in glass, from 32°, to 212°
do. from 212°, to 392°
do. Water saturated with common salt, do. Sulphuric ether,
do. Fixed oils,
great, as is certainly the case with mercury ; his ex-
Dr. Young, in his valuable Catalogue Raisonnée, Natural Philosophy, vol. ii. p. 391, gives the following table of the expansions of water, constructed from a collation of experiments by Gilpin, Kirwan, and Achard. He says that the degrees of Fahrenheit's thermometer, reckoning either way from 39°, being called f, the expansion of water is nearly expressed by 2282 (1 — ·0027) in 10 millionths; and the diminution of the sp. gr. by •0000022/" - ·0000000047213 This equation, as well as the table, is very important for the reduction of specific gravities of bodies, taken by weighing them in water.
102 10.99246 Kirwan 0.00754
0.02417 167 0.97480 Deluc 0.02520 182 0.96900 K. 0:03100 202 0.96145
0.03855 212 0.95848
0.03198 0.04005 0.04333
M. Gay Lussac has lately endeavoured to discover some law which should correspond with the rate of dilatation of different liquids by heat. For this purpose, instead of comparing the dilatations of different liquids, above or below a temperature uniform for all, he set out from a point variable with regard to temperature, but uniform as to the cohesion of the particles of the bodies; namely, from the point at which each liquid boils under a given pressure. Among those which he examined, he found two which dilate equally from that point, viz. alcohol and sulphuret of carbon, of which the former boils at 173.14°, the latter at 115.9°, Fahrenheit. The other liquids did not present, in this respect, the same resemblance. Another analogy of the above two liquids is, that the same volume of each gives, at its boiling point, under the same atmospheric pressure, the same volume of vapor; or, in other words, that the densities of their vapors are to each other as those of the liquids at their respective boiling temperatures. The following table shows the results of this distinguished chemist :
Table of the Contractions of 1000 parts in volume, by cooling.
Sulphuret of Carb.
Contract Ditto Contract Ditto Contract Ditto Contract
Ditto by expt. calculated. by expt. calculated. by expt. calculated. by expt. calculated.
Their respective boiling points are:
some to apply than the above ru.e. Vapors, Water
Cent. = 212° F. when heated out of contact of their respective Alcohol
173 liquids, obey the same law as gases ; a discovery Sulphuret of carb. 46.60
126 due to M, Gay Lussac. Sulphuric ether 35.66
2. Of the change of state produced in bodies by The experiments were made in thermometer caloric.—The three forms of matter, the solid, vessels hermetically sealed.
liquid, and gaseous, seem immediately referrible Alcohol, at 78:41° cent., produces 488:3 its to the power of heat, modifying, balancing, or volume of vapor.
subduing cohesive attraction. The system of Suiphuret of carbon, at 46.60° cent., produces the world presents magnificent effects of attrac491.1 'its volume of vapor.
tion dependent on figure. Such are the phenoEther, at 35.66° cent., produces 285.9 its mena of nutation and the precession of the volume of vapor.
equinoxes, produced by the attractions of the Water, at 100.00° cent., produces. 1633-1 its sun and moon on the flattened spheroid of volume of vapor.
the earth. These sublime phenomena would Mr. Dalton has the merit of having first not have existed had the earth been a sphere: proved that the expansions of all aëriform bodies, they are connected with its oblateness and rotawhen insulated from liquids, are uniform by the tion, in a manner which may be mathematically same increase of temperature; a fact of great deduced, and subjected to calculation. The inimportance to practical chemistry, which was vestigation shows, that this part of the attraction fully verified by the independent and equally dependent on figure decreases more rapidly original researches of M. Gay Lussac on the than the principal force. The latter diminishes subject, with a more refined and exact apparatus. as the square of the distance; the part dependThe latter philosopher demonstrated that 100 in ent on figure diminishes as the cube of the volume at 32° Fahrenheit, or 0° cent., became distance. Thus also, in the attractions which 1.375 at 212° Fahrenheit, or 100° cent. Hence hold the parts of bodies united, we ought to exthe increment of bulk for each degree Fahrenheit pect an analogous difference to occur. Hence is set = 0.002083 = jk; and for the centigrade the force of crystallisation may be subdued, bescale it is = 0.00375 =
To reduce any
fore the principal attractive force is overcome. volume of gas, therefore, to the bulk it would When the particles are brought to this distance, occupy at any standard temperature, we must they will be indifferent to all the positions which multiply the thermometric difference in degrees they can assume round their centre of gravity; of Fahrenheit by 0·002083, or aku, subtracting the this will constitute the liquid condition. We product from the given volume, if the gas be
must now content ourselves with stating the reheated above, but adding it, if the gas be cooled sults as much as possible in a tabular form. below, the standard temperature. Thus twentyfive cubic inches at 120° Farenheit will at 60° Taele of the Concreting or Congealing Temoccupy a volume of 217; for to X 60 = - 9 = b;
peratures of various Liquids by FAHRENHEIT'S
Scale. and =3, which, taken from 25, leaves 217. A table of reduction will be found under Gas. Sulphuric ether.
46° When the table is expressed decimally, indeed, Liquid ammo to six or seven figures, it becomes more trouble. Nitric acid, sp. gr.
1.424 40.5 Vol. \I.